The use range of asphalt used as a material for road pavement and waterproofing has been considerably restricted due to cracking at low temperature, plastic deformation at high temperature, etc. Therefore, studies and applications on various asphalt modifiers have been actively progressed in order to improve the disadvantage of asphalt.
As the asphalt modifier, various polymer materials, such as olefin/acrylic copolymer, vinyl aromatic hydrocarbon/conjugated diene random copolymer, vinyl aromatic hydrogen/conjugated diene block copolymer, etc., can be used. Among others, the vinyl aromatic hydrogen/conjugated diene block copolymer has been the most widely used since it can remarkably increase the use temperature range and lifetime of asphalt.
Meanwhile, in the asphalt modifying process, it is very important to dissolve and disperse the polymer materials in asphalt. Generally, the solution rate of asphalt modifier is slow, thereby having a direct effect on productivity. In order to improve productivity, the solubility of asphalt can be increased by controlling the molecular weight and molecular structure of the polymer material, which deteriorates the final mechanical physical properties.